1. Field of the Invention
The invention relates to a vehicle, which includes a frame, a pedal crank which is mounted on the frame in a manner so that it can rotate about a first axis, a drive motor, and a drive belt or drive chain for transmission of force from the drive motor to a drive wheel, with the drive wheel being mounted resiliently on the frame via a rocker.
2. The Prior Art
It is known to provide a vehicle such as a bicycle with a drive motor which drives the vehicle and at the same time with a pedal crank which is driven by the user of the vehicle. Substantially higher speeds can be achieved with such a vehicle as compared with conventional bicycles which are driven exclusively by muscular power As a result of the high travelling speed, efficient suspension of the wheels of the vehicle is of higher important than would be the case in conventional bicycles. The suspension of the rear wheel of such a vehicle is usually made via a rocker which is fastened in a swiveling manner to the frame and which rests on the frame by means of a spring or damping element. The drive of the drive wheel occurs in many cases through a chain which is guided on the one hand via a first gearwheel held on the frame and on the other hand via a second gearwheel fastened to the drive wheel. As an alternative to the chain, it is possible to provide a drive belt which is arranged as a toothed belt or a ribbed V-belt. In conventional vehicles, the drive chain or drive belt is held in the tensioned state by a tensioning member which especially compensates any changes in the distance between the first gearwheel and the second gearwheel. With such a drive arrangement, however, torque can be transmitted onto the drive wheel only in one direction, which means that it is only possible that the drive motor drives the drive wheel in the forward direction. It is not possible with this arrangement however to implement regenerative braking which provides the torque in the side opposite of the drive moment.
It has now been seen that this limitation for electrically driven vehicles is obstructive and impairs potential flexibility in the application and increase in the range of a battery charge.
It is the object of the present invention to avoid such disadvantages and to provide a solution which offers the highest possible flexibility in the arrangement of a drive for such a vehicle.